package com.neo.debade.web.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.http.HttpSession;

/**
 * 去掉URL rewrite时添加的　jsessionid 
 * @author zhong_xin
 * @version 1.0 Apr 10, 2013
 */
public class JSessionIdFilter implements Filter { 

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        
		// skip non-http requests
        if (!(request instanceof HttpServletRequest)) {
             chain.doFilter(request, response);
            return;
         }

         HttpServletRequest httpRequest = (HttpServletRequest) request;
         HttpServletResponse httpResponse = (HttpServletResponse) response;
         
//         System.out.println("session id : " + httpRequest.getSession().getId());
        // clear session if session id in URL
        if (httpRequest.isRequestedSessionIdFromURL()) {
             HttpSession session = httpRequest.getSession();
            if (session != null) session.invalidate();
         }

        // wrap response to remove URL encoding
         HttpServletResponseWrapper wrappedResponse = new HttpServletResponseWrapper(httpResponse) {
             @Override
            public String encodeRedirectUrl(String url) {
                return url;
             }
         
            public String encodeRedirectURL(String url) {
                return url;
             }
           
            public String encodeUrl(String url) {
                return url;
             }
           
            public String encodeURL(String url) {
                return url;
             }
         };

        // process next request in chain
         chain.doFilter(request, wrappedResponse);
     }

    /**
      * Unused.
     */
    public void init(FilterConfig config) throws ServletException {
     }

    /**
      * Unused.
     */
    public void destroy() {
     }
}
